COMAL COUNTY, Texas (CBS) - You may think of bats as spooky creatures that fly in the dark of night, but it turns out they have a major impact on agriculture and tourism in Texas.
Just outside of San Antonio, the Bracken Cave Preserve is the summer home to the world’s largest bat colony, with more than 15 million Mexican free-tailed bats living there from about March to October.
Around dusk each day, the wildlife perks up and the millions of bats begin to swirl out of the cave, ready to roam the night skies. "These emergences are so intense-they show up on the doppler radar like clouds forming over these bat roosts," said Fran Hutchins, Director of Bat Conservation International's Bracken Cave Preserve.
Bat Conservation International hosts groups of visitors to educate them about bats and expose them to the unique experience of the bats emerging from the cave. "When you come out and see the batnado….when you can see it and hear it and smell it, it's an emotional experience," said Hutchins.
"They're everywhere! There are so many of them," said Sam Michaels visiting the preserve for the first time. "It's like unbelievable; I had no idea."
While the experience draws bat lovers and tourists to South Texas, the bats also play a huge role in pest control for area farmers.
"Not having bats is a world filled with a lot of biting bugs," said Hutchins. "This colony is going to eat about 147 tons of bugs tonight, real important to our local farmers," he said.
The bats can fly as high as 10,000 feet and travel around sixty miles from the cave, hunting for food, which in turn helps preserve local crops.
Bat biologists estimate the creatures can save farmers billions of dollars in pest control annually nationwide. Cotton is one of the crops most benefited, along with corn, sorghum, even Texas pecans.
John and Jimma Byrd own a pecan orchard in San Saba, Texas. They built a bat house on their property after discovering they had several species of bats on their farm. "They're working every night too. You don't have to pay them, nothing but a place to live," the Byrds joked.
It's a win-win for the Byrds who farm organically since the bats prey on pests such as moths, that like their pecans.
"All the old time pecan farmers used to say the bats are good for an orchard…and of course I've suspected that," said John Byrd. "What we're doing is not something that's new, but it's actually old," he continued. Byrd added "It enhances our appreciation for our farm and everything that co-exists."
Meanwhile, the millions of bats that live at Bracken Cave have now headed to Mexico where they’ll spend the winter, returning next spring.